326 Reduction of Sound Power Radiating from a Thin Plate by Adding a Hollow Experimental Validation of the optimal solution and Optimization in consideration of Damping

Abstract

This paper describes the optimization method to reduce sound power radiating from a peripherally fixed thin rectangular plate by adding a rectangular hollow. The sound power at the fundamental frequency of the plate was set as an objective function. The location and size of the hollow were set as design variables and were optimized with the Feasible direction method.To improve the estimation error, the modal damping ratios after the structural modification were estimated based on the assumption of proportional viscous damping. The sound power radiating from optimized plate with the estimated modal damping ratio reduced by 5.3dB.